Process of electric welding.



M. LACHMAN. PROCESS OF ELECTRIC WELDING. APPLICATION IILBD MAR. a, 1908.

Patented Jan. 4, 1910.

5 nvegtor:

UNITED STATES PATENT OFFICE;

MAURICE LACI-IMAN, OF NEW YORK, N. Y., ASSIGNOR T0 UNIVERSAL ELECTRICWELDING COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

rnocnss or nnncrnrc WELDING.

Specification-of Letters Patent.

Patenttiu n. 4, 1910.

Application filed March 3, 1908. Serial No. 418,950.

To all whom it may concern:

Be it known that I, MAURICE LAOHMAN, a citizen of the United States,residing in the city of New York, county'of New York, and State of NewYork, have invented certain new and useful Processes of Electric\Velding; and I do hereby declare the following to be a full, clear,and'exact description of the same, such as will enable others skilled inthe art to which itappertains to make and use the same.

This invention relates to processes of electrical welding and consistsin a method/bf electrically welding rods, teeth, tines and similarelongated metal objects to plane surfaced metal objects, which comprisesthe provision upon such plane surfaced objects of a lug or projection ofcrossisectional area about corresponding to that of the. other elementto be welded thereto, placing such element and such lug in abuttingcontact, passing a welding current through such contact andsimultaneously pressing the metal objects together until coalescence andintegral union occur at such contact, and finally dis-.

continuing the welding current; all as more fully hereinafter set forthand claimed,

The present'invention is particularly applicable to, welding the buttends of rods, teeth, tines and similar elongated objects to "planesurfaced metal objects of relatively large surface area and thickness,as compared with the cross sectional area of the elongated objects to bewelded thereto.

In the present invention, the holding element, as, for instance, theback of a rake, is broader than the end of the tine to be weldedthereto, and for this reason, the relatively broad surface on the backof the rake, to which the tine is to be welded, is provided with a spuror lug either projecting from its surface or countersunk therein, de-

pending upon the relative thickness of the back of the rake, for whenthe back of the rake is very thick it is impracticable to form.

lugs which project above the surface of the metal.

According to the present invention the spurs or lugs on the back of therake, for example, can be made by a suitable die'or press; whichwillfforxn a continuous groove on the relatively broad. surface of the.back of the rake, so as to form. an isolated surface of metal or lug towhich the end of the time isv to be welded, the number of isolated surd,faces or lugs depending upon the number of tines which areto be weldedto the back of the rake or other article. The relative cross-sectionalarea of the isolated surface or lug may be varied by varying the shapeand depth of the continuous groove, which may that when the back of therake, and the tines are put in a suitable machine and a welding currentof electricity is passed through the same, the isolated surface or lugand the end of the tine will be heated equally and a coalescent andintegral union can readily be effected, after which the welding currentisv cu off. Before the. metal has cooled at the ppint of weld union thesame is preferably upset so as the metal will fill the continuous grooveand also form a continuous flange which bears upon the top of the backof the rake, thereby stiffening the tines, the bur, if any,'being ressedinto. the continuousgroove so as to 'eave a. neat, welded joint; at thepoint ofwelded union.

Referring to the drawings: Figure 1 is a perspective view of a portionof the back of; a rake,.sho.wing one form of isolated contact surface,Ifig. 2. a View similar to Fig. 1,

figure also shows'a tine spaced above the isolatedcontaet surface; 'Flg.4.- is a detail View in cross section showing the tine welded to theback of the rake; Fig. 5 is a view similar to Fig. 3, in which theisolated contact surface is level with the surface ofthe back of therake. The figure also shows an alternate forin of tine; Fig. 6 is aview.-similar to Fig. 5, showing in cross section the tine welded to theback of therake; Fig. 71 1s a perspective View of a ti'ne,.weldecl tothe flat surface of the. back of a piec of Dela-1 tively thick metal.

- In. the. drawings Ar designates a. portion. Of the hack of 8.1 13 8.-which rovided in isolated surfac s or lugs 13 Ina e'by formingcontinuous grooves. C. on the, surface of the back. A. by means of a.suitable die.. The

relative cross-sectional area of the isolated have been welded togetherand upset so as to the rake A, the isolated surface B and the end of thetime D will be heated to substan- I of the metal as shown in Fig. 3, bymeans .when a welding current ispassed-through surfaces or lugs may bevaried by varying 1 close the grooves and form a flange about the shapeof the grooves C which may be the end of the tines. round or square, asshown in Figs. 1 and 2, In order to insure a su table flange form- 01any other shape as desired, depending ing about the base of the tine,when the same largel 'upon the shape of the end of the t has been weldedto the back of a rake, the tines which are to be welded thereto. tine Dis preferably made of a little greater The isolated surfaces or lugs Bare of cross sectional area near its lower end and such a crosssectional area, and the grooves sharpened as shown in Fig. 5, so as tobe of C are of such a depth, that when a current approximately the samecross-sectional area of electricity is passed thro gh th b k f as theisolated surface B so that when the same have been welded together thereis abundant metal at the base of the tine D to tially the sametemperature. After the end of the time 1) and isolated surface B havebeen heated to a welding temperature, the same are forced together tocomplete the weld, the same being forced together so that the weldedmetal will be upset at the point t of welded union so as to entirelyclose the continuous groove C, the same being not necessarily weldedtogether, although the outward appearance of the welded union does notdisclose the groove C, as the isolated surface B and the end of the tineD are upset to fill the groove C while the lower end of the tine D isalso upset so as to form an upset portion-or continuous flange E, whichbears upon the top of the rake and assists in materially stiffening thetines D while at the same time giving a finished appearance to thewelded union, as shown in Fig.7.

If the metal A is of relatively thin metal, the lug B can be forcedabove the surface ing of the groove G and obviate-the appeared union asshown in Fig. (3.

From the above description it will be seen that any-shape of tine can bewelded to a relatively thin piece of metal or to a relatively thickpiece of metal by varying the shapes and depths of the grooves so as tomake differently shaped isolated surfaces on the face of the metal towhich the time is to be welded, the grooves in every instance beingpreferably made continuous so that a continuous flange can be formed byupsetting the base of the tine, thereby obviating the removal of any'burto give a finished appearance to the welded union.

What I claim is 1. The process of electrically welding parts to formobjects of angle or T-shapes, which consists in forming in the surfaceof one part a continuous groove to reduce the superficial area of suchpart at the point of f a it bl di or punch so as t l v a intended weldto form an isolated surface or countersunk recess F which is preferablyof the same shape as the isolated surface 15. By so doing it will beseen that there is very little metal connecting the isolated surface Bwith the back of the rake A which prevents the heat being carried awayby conduction and acilitates the isolated surface B being bro ght to awelding temperature simultaneously with the end of the tine D when awelding current is passed through the'same. By prbviding the recess F itwill also be seen that the groove C can be of less depth than wouldotherwise be the case. When the back of the rake A is made of relativelythick metal, only the grooves O are'used as shown in Fig. 5, the groovesbeing made of sufiicient depth to heat the isolated surface B and theend of the tine D to approximately the same temperature said isolatedsurface or lug, passing a welding current through said parts andsimultaneously therewith forcing them together to complete the weld thencontinuing to force the pieces of metal together while in a heatedcondition so as to form a continuous flange which rests upon the surfaceof the first named part adjacent the point of welded union, andinterrupting the flow of current as soon as the two abutting surfaceshave formed a weld union.

butt end of anielongated piece of metal to the broad fiat surface ofanother piece of metal, which consists in forming in the a continuousgroove to reduce the superficial area of such part at the point ofintended Weld to form an isolated surface or lug, placing the butt ofthe elongated piece of metal on said isolated surface or hm, passing awelding current through sai parts and simultaneously therewith forcingthem together to complete the weld, then continuing to force the piecesof metal together the same.

By. referring to Figs. 3 and 5, it will be seen that-the end of thetines are preferably a little larger in cross section than thecorresponding surfaces to which they are to be welded, although they arenot so large as to come'in cohtac't. with the back of the rake adjacentthe isolated surfaces until the same continuous flange at the point ofwelded form an excellent flange and insure the closn l ance of any bur011 the outside of the weld lug, placing the butt of the other part on'2. The process of electrically welding the while in a heated conditionso as to form a broad flat surface of the other piece of metal union,and interrupting the flow of current as soontas the two abuttingsurfaces have formed a weld union.

3. The. process of electrically welding parts to form objects of angleor T-shapes, which consists in forming in the surface-of one part acontinuous groove so as to form an isolated surface or lug, the undersurface of said'part beneath said isolated surface or lug being providedwith' a recess which together with said continuous groove reduces theconductivity of the isolated surface or lug with the ad acent metal,lacing the butt of the other part" on said isolated surface or, lug,passing a. welding current through said ing witnesses.

MAURICE LACHMAN. Witnesses LEO J. MArrY,

FnANK E. RAFFMAN.

